How come I got so drunk and passed out?

Ok so i typically (within the last 3 months) go out once a week and have between 2-3 drinks.

They are usually Vodka soda’s or Long island’s. I don’t mix them up in the night, so i pick one and only drink that.

If I start at say 6pm I might be done by 8pm. Sometimes I have my first 2 within an hour and then space out my 3rd drink. I have a nice buzz, but I can still talk, walk etc. I NEVER puke or pass out. Ever.

Recently I went to a party and they had malibu mixed with juice. I started drinking at 9pm and had 4 solo cups full within 2 hours. By 11:30pm I completely passed out, wasnt responsive, couldnt walk etc.

What is shocking is even on my 2-3rd solo cup I didnt feel that buzzed yet which is why I kept drinking, plus I normally have 2-3 drinks anyways, so I thought I would be fine. Until I woke up the next morning and didn’t remember half of the night or how I got home. :(

Why did that happen with the malibu drink with juice and not the vodka sodas/long islands?

I’m very confused as that has never happened to me before. Thankfully I was at a house with very good friends and they took care of me to make sure nothing bad happened.

This actually scared me extremely bad. I’m terrified to go out with friends again and drink (wont be drinking malibu for sure!!) because what if it happens again.

I’m scared to even have one drink again because I don’t understand how I got so messed up from just one extra drink than normal and I didnt even feel a buzz on my 3rd drink.

I don’t believe my drink was laced as I had my drink in my hand the whole night, and one of my friends was sipping on my drink too and didnt have any effects of being drugged.